System and apparatus for tunneling service of explicit multicast

Abstract

The present invention relates to a system and apparatus for tunneling service of explicit multicast, to efficiently transmit an explicit multicast of a packet to plural destinations. A tunnel ingress node is receives an explicit multicast packet from a sender terminal, which the explicit multicast packet has to be transmitted to plural addressee terminals. And, after the tunnel ingress node recognizes tunnel egress nodes using plural addresses terminal's address in the explicit multicast packet, it creates a tunnel header comprising transmission destinations based on the list of the recognized tunnel egress nodes. And then, the tunnel ingress node creates a tunnel packet encapsulated with the explicit multicast packet and the tunnel header, transmits the tunnel packet to the tunnel egress nodes. The tunnel egress nodes extract the tunnel header from the tunnel packet, and transmit the explicit multicasting packet to plural addressee terminals using the destination address of the tunnel header.

1. An explicit multicast tunneling method, comprising:
 receiving an explicit multicast packet from a source to be sent to a plurality of destinations, wherein the source and the plurality of destinations are in data communication with a tunnel ingress node and at least one tunnel egress node, respectively, and wherein the explicit multicast packet includes addresses of the plurality of destinations therein; 
 duplicating, at each tunnel egress node, the explicit multicast packet as many times as the number of destinations that are in data communication with the corresponding tunnel egress node; 
 modifying destination addresses of each of the duplicated multicast packets such that each destination does not repeatedly receive the same multicast packet; and 
 transmitting each of the modified multicast packets to the plurality of destinations based on the modified destination addresses. 
 
   
   
     2. The method of  claim 1 , wherein the at least one tunnel egress node comprises a plurality of tunnel egress nodes which are in data communication with the plurality of destinations, respectively. 
   
   
     3. The method of  claim 2 , further comprising:
 determining the plurality of tunnel egress nodes based on the addresses of the plurality of destinations within the received explicit multicast packet so as to generate an address list of the plurality of tunnel egress nodes; 
 generating a tunnel header having the address list of the plurality of tunnel egress nodes as a destination address; 
 encapsulating the explicit multicast packet with the generated tunnel header so as to generate a tunnel packet; 
 sending the tunnel packet to the plurality of tunnel egress nodes via a plurality of transit nodes, located between the tunnel ingress node and the plurality of tunnel egress nodes, wherein the tunnel packet is duplicated, at each transit node, as many times as the number of subsequent nodes that are in data communication with the corresponding transit node; and 
 separating, at each tunnel egress node, the tunnel header from the tunnel packet so as to obtain the explicit multicast packet. 
 
   
   
     4. The method of  claim 3 , wherein the tunnel header comprises a tunnel ingress node address field, a link local multicast address field, an address list of tunnel egress nodes field, and a bitmap. 
   
   
     5. The method of  claim 3 , wherein the sending comprises:
 determining a next route of the tunnel packet; and 
 modifying the destination address of the tunnel header according to the determined next route. 
 
   
   
     6. The method of  claim 1 , wherein the at least one tunnel egress node is one tunnel egress node in data communication with the plurality of destinations, and wherein the duplicating is performed at the one tunnel egress node. 
   
   
     7. An explicit multicast tunneling system, comprising:
 a tunnel ingress node configured to receive an explicit multicast packet from a source to be sent to a plurality of destinations, wherein the source is in data communication with the tunnel ingress node, and wherein the explicit multicast packet includes addresses of the plurality of destinations therein; 
 at least one tunnel egress node being in data communication with the plurality of destinations; and 
 at least one transit node located between the tunnel ingress node and the at least one tunnel egress node, 
 wherein each of the at least one tunnel egress node is configured to duplicate the multicast packet as many times as the number of destinations that are in data communication with the corresponding tunnel egress node, and 
 wherein the at least one tunnel egress node is configured to modify destination addresses of each of the duplicated multicast packets such that each destination does not repeatedly receive the same multicast packet, and is configured to transmit each of the modified multicast packets to the plurality of destinations based on the modified destination addresses. 
 
   
   
     8. The system of  claim 7 , wherein the source comprises a server and each of the plurality of destinations comprises an end user's computing device. 
   
   
     9. The system of  claim 7 , wherein the at least one tunnel egress node comprises a plurality of tunnel egress nodes which are, respectively, in data communication with the plurality of destinations. 
   
   
     10. The system of  claim 7 , wherein the tunnel ingress node is further configured to i) generate a tunnel header having an address list of the at least one tunnel egress node as a destination address, ii) encapsulate the explicit multicast packet with the generated tunnel header so as to generate a tunnel packet and iii) send the tunnel packet to the at least one tunnel egress node via at least one transit node, wherein each of the least one transit node is configured to duplicate the tunnel packet as many times as the number of subsequent nodes that are in data communication with the corresponding transit node, and
 wherein each of the at least one tunnel egress node is further configured to separate the tunnel header from the tunnel packet so as to obtain the explicit multicast packet, and duplicate the explicit multicast packet as many times as the number of destinations that are in data communication with the corresponding tunnel egress node.